The current air conditioning systems and air conditioners do not require large maintenance. However, it is advisable to visit the agency or a specialised workshop at the beginning of each season of the year (as a preventive service).
Any automotive air conditioning system employs 4 basic parts; a mechanical compressor driven by the vehicle engine; an expansion valve which is a restriction to where the compressor pumps; and 2 heat exchangers; the evaporator and the condenser. In addition, the refrigerant flowing through the system is required.
The compressor uses engine power to compress and circulate the refrigerant gas through the system. The refrigerant passes through the condenser (located in front of the radiator) on its way from the compressor outlet to the expansion valve. The refrigerant passes from the expansion valve to the evaporator (located inside the car) and, after passing through the evaporator pipe, is returned to the compressor.
When the compressor goes into operation, it draws refrigerant from the evaporator pipe and pushes it towards the condenser pipe, decreasing the evaporator pressure and increasing the condenser pressure. When the proper operating pressures are established, the expansion valve opens, allowing the refrigerant to return to the evaporator at the same speed that the compressor is removing it. Under these conditions, the pressure at each point of the system reaches a constant level, but the condenser pressure will be much higher than the evaporator pressure.
The pressure in the evaporator is low enough that the boiling point of the refrigerant is quite lower than the interior temperature of the vehicle, therefore, the liquid evaporates, removes heat from the inside and leaves the evaporator as gas. The heat effect produced by passing the refrigerant through the compressor prevents the gas from liquefying and causes it to be discharged from the compressor at very high temperatures. This hot gas passes to the condenser. The pressure on this side of the system is high enough so that the boiling point of the coolant is well above the outside temperature. The gas will cool until it reaches its boiling point and will condense as the heat is absorbed by the outside air. The liquid refrigerant is forced back through the expansion valve by the pressure of the condenser.
The air conditioning system is one of the greatest technical achievements achieved for the sake of comfort on board a vehicle. The objective of the system is to reach a temperature of around 21 / 25º C in a fast and maintained way, with an operation similar to that of a refrigerator. The air conditioning system what it does is extract the heat from the interior and expel it to the outside.
The air conditioning system is supported by a cooling fluid that in modern cars is R-134A (tetrafluoroethane), which is friendly to the environment. The one used until a few years ago and called Freon 12, or simply R12, was found to damage the ozone layer and also, in the presence of humidity, became harmful to human health.
Remember to contact the experts, JB Euro Auto Service to provide you with top maintenance services and keep your car running at full potential.
The secrets of air conditioning
On several occasions we have observed water dripping under the vehicle when the air conditioning system is working. This is completely normal, due to the condensation of water on the outside of the pipes (the evaporator draws water from the humidity of the air by dehumidifying it).
Important tips for the best use of air conditioning
- Open the windows when starting the car, to remove the hot air and then close them to turn on the air conditioning
- Keep the car closed while the air conditioner is running
- Do not turn on the air conditioner, if it is not necessary to lower the temperature too much; a better option is to turn on the fan
- Carry out general cleaning of the equipment, remove dust and mould, and paint it to avoid oxidation
- Check that all gaskets (doors) and windows of the car are not broken or cracked
- Remove the garbage that is in the base of the windshield, since it obstructs the entrance of the outside air
- Do not obstruct the outputs of the air conditioning of the dashboard, (exit to the windshield and frontal exits) nor the exit towards the floor, for a better comfort of the passengers. Some cars have an exit to the rear seats
- The air outlet temperature is between 10 and 15 ° C, so the grilles should always be oriented so that the air diffuses throughout the car, and not directly to the occupants
- Do not overcook, it must be taken into account that for each degree required to air conditioning below 25 ° C, you will be consuming approximately 8% more energy
- You must use your air conditioner at least once a week (even in the winter) for at least 2 minutes, the purpose of which is to circulate the oil in the compressor to always keep the equipment lubricated, otherwise this ignition occurs, the compressor fails, and the equipment will not work.
The importance of air conditioning maintenance
The objective of maintaining the air conditioning equipment, is to maintain it in optimal conditions and thus minimize more expensive failures for the user.
Normally, preventive or routine maintenance consists of:
- Evaporator cleaning (usually aluminium and expensive part)
- Change of the filter drier (dehydrating bottle that tries to collect or absorb the internal humidity of the liquid refrigerant product)
- Replacement of the expansion valve (controls the flow of refrigerant to the evaporator)
- Change of seals (rubber rings)
- Make a vacuum to the system that should last at least 40 minutes
- Add oil to the compressor
- Finally load it with its respective refrigerant which can be R-12 (CFC) or R-134 (HFC). A system that needs 10% of refrigerant, will cost 20% more in its operation
Without regular maintenance, the air conditioner loses approximately 5% of its original efficiency for each year of operation, if it is given adequate maintenance it will be possible to maintain 95% of the original efficiency.
Keeping the car in good condition will help you travel with greater safety in addition to allowing you to drive the car for much longer and someday sell it. Remember to contact the experts, JB Euro Auto Service to provide you with top maintenance services and keep your car running at full potential.